1. Field of the Invention
The present invention relates to a digital item adaptation, particularly to a method for generating an adaptive usage environment descriptor of the digital item.
2. Description of the Related Art
In activities related to an electronic commerce, such as creation, production, transaction, transmission, management, storage and consumption of multimedia data, there have been demands for flexible, transparent and augmented use of multimedia resources.
Specifically, considering a tendency to widely use an electronic commerce with an advance of Internet, a non-existence of a declaration model for the treatment unit of the multimedia data used in the electronic commerce is a latent factor that may cause a confusion of the electronic commerce.
In consideration of these points, a declaration of the digital item is stipulated in MPEG-21 of an international standard organization ISO/IEC SC29/WG11, maximally taking consideration into users of an electronic commerce business model (the users includes all subjects related to the electronic commerce, such as digital item creator, provider, distributor, consumer, intellectual property right holder, financial service provider, electronic commerce supervisor, and the like). There has been an attempt to make the digital item to be an international standard that is flexible, coherent and compatible on the basis of relationship between the subjects of the electronic commerce or their associated descriptions.
Accordingly, there have been demands for a declaration model of the digital item, which can consider relationship between the subjects (or users) of business model configuration in the electronic commerce or the associated descriptions and achieve the electronic commerce without regard to kinds of networks or terminals.
The declaration model of such a digital item should have a compatibility, a coherence and flexibility as a minimum unit of multimedia data in the activities of the electronic commerce, such as creation, production, transaction, transmission, management, storage and consumption of the multimedia data used for the electronic commerce.
The digital item is a fundamental unit of whole activities, such as creation, production, transaction, transmission, management, storage and consumption of the multimedia contents that are valuable as an intellectual property under wired/wireless environments. Generally, the digital item consists of three components. In other words, the digital item can include: a RESOURCE (for example, movie or music itself) which is an individual asset or content; a DESCRIPTOR (for example, title of movie or music, genre, name of author, summary of contents, usage conditions, or regulation of the contents) describing the contents and their usages; and configurational elements (for example, “CHOICE”, “SELECTION” and “CONDITION”) configuring the digital item.
In addition to the resource itself, the digital item can further include metadata. The metadata contains a DESCRIPTOR describing the resource, a SELECTION element that can be selected by the user, a CHOICE element that is a bundle of SELECTION elements, and each of the SELECTION element and the CHOICE element contains a CONDITION element that represents validity under a specific condition. Additionally, the digital item includes many COMPONENTS (an actual resource (music file or graphic file) and a DESCRIPTOR). Among them, in order to make it possible for the user to select desired COMPONENT and configure suitable digital item, the digital item and the COMPONENT contain the CONDITION element that requires a specific condition set by the user. Specifically, the CONDITION refers to the SELECTION element. If the SELECTION element selected by the user exists in the reference list, the corresponding CONDITION is “true”, and if not, it is “false”.
As described above, the CHOICE element describes a set of related SELECTION elements, and the CONDITION element describes pre-satisfied conditions.
Many digital items that are previously generated are reconfigured to generate new digital items (composite digital items)
For example, image digital items are configured to generate a composite digital item, which is called an album. In that case, each of the image digital items is an external storage digital item existing in an independent storage unit. In order to contain the image digital items, the new album digital item contains REFERENCES that are accessible to them.
Additionally, in case the desired digital items are configured using the CONDITION elements, an efficient representation of the CONDITION is an important factor that determines an efficiency of comparative operation and a capability to represent the CONDITION. There is a demand for an efficient representation of the CONDITION, which considers characteristics of condition comparison objects.
FIG. 1 illustrates a structure of a declaration model of a digital item.
As shown in FIG. 1, the digital item is described with a DECLARATION, a CONTAINER and an ITEM in a Digital Item Declaration Language (DIDL).
A COMPONENT includes a RESOURCE such as audio, video, graphic and text, an ANCHOR indicating the RESOURCE, and a DESCRIPTOR describing the COMPONENT. An ITEM is a grouping of sub-ITEMS and/or COMPONENTS. Also, A CONTAINER is a structure that allows ITEMS and/or CONTAINERS to be grouped.
FIG. 1 shows that the digital item can include other digital items, and a reference component accessible to an external storage digital item is defined in the digital item.
The digital item shows a mechanism that can select desired configuration using the CHOICE element and the SELECTION element. Additionally, the user can configure desired digital item by using the CONDITION element. An efficient representation of the CONDITION is an important factor that determines an efficiency of comparative operation and a capability to represent the CONDITION. Accordingly, it can be seen that there is a demand for an efficient representation of the CONDITION, which considers characteristics of a condition comparison object.
As described above, it is necessary to provide a description that can make the user experience various multimedia contents in the most optimum state according to various usage environments. In other words, it is necessary to provide a description that can make the user experience the multimedia in the most optimum state according to a capability of user terminal, a capability of network, a capability of a delivery layer, a user characteristic such as preference and gender, a natural environment characteristic, and a capability of provided service. For the purpose of these descriptions, a Digital Item Adaptation (DIA) should basically provide a descriptor on the usage environment.
On the basis of the requirements, various usage environment descriptors should be described or processed to cope with the tendency that various multimedia contents are provided and usage environments of the contents are extensively varied. Accordingly, there is a demand for a method of generating a descriptor that defines which environment descriptor is preferred among various and mass environment descriptors in the digital item adaptation. Additionally, an “AlternativePreference” descriptor is required as second best policy for the environment descriptors determined by the preference.
In other words, in the latter case, there is a demand for a method of providing second best contents for the required contents by defining the descriptor that provides a criteria of the alternative selection of the environment descriptor corresponding to the environment descriptor selected by the digital item adaptation.